1. Field
Example embodiments relate to a method of reworking a semiconductor substrate. Other example embodiments relate to a method of reworking a semiconductor substrate and a method of forming a pattern of semiconductor device using the same without damage to an organic anti-reflective coating (ARC).
2. Description of the Related Art
Recently, in an attempt to manufacture semiconductor devices having faster operation speeds accompanied by a larger capacity, methods of manufacturing a more reliable semiconductor device having an increased density and/or faster response speed are being developed. In order to increase the density of the semiconductor device, the requirements for microfabrication technologies (e.g., photolithography) are strict.
The photolithography, In order to form fine patterns that are applied to a semiconductor device, photolithography is performed using a photoresist pattern as an etching mask. An anti-reflective coating (ARC) may be formed on an object layer before the photoresist film is formed in order to form the photoresist pattern. The ARC is used to reduce reflections of an etching object layer from light produced during an exposure process when the photoresist is patterned in a photolithography process.
The ARC prevents (or reduces) a standing wave effect generated by interference between a light incident to a photoresist film from the exposure and a light reflecting from the etching object layer. The ARC may prevent (or reduce) unusual reflection in the topography due to patterns formed in a preceding process and diffused reflection at edges.
Prior to forming the photoresist pattern, the precision of a critical dimension (CD) of a fine circuit pattern may be increased by forming the ARC such that the process latitude for manufacturing conditions increases. The ARC having the above-mentioned characteristics may be categorized as an inorganic ARC including inorganic materials and an organic ARC including organic materials. The inorganic ARC has increased adhesion to the topography of lower object layer and may not be easily removed in a subsequent process. The inorganic ARC may not adhere as well as the organic ARC to a formed photoresist pattern. As such, it is more desirable to use the organic ARC than the inorganic ARC.
In a photolithography process using the organic ARC, an organic ARC may be formed by performing a baking process after spin-coating organic ARC materials on an etching object layer. A photoresist pattern may be formed by performing an exposure process using an exposure mask, a baking process and/or a developing process after forming a photoresist film on the organic ARC. Finer patterns may be formed on a semiconductor device by etching the etching object layer exposed by the photoresist pattern.
The above-mentioned photolithography process varies depending on whether a profile of the photoresist pattern is appropriate for an etching mask. A defect may occur in the profile of photoresist pattern due to variables generated during the spin-coating process, baking process, exposure process and/or developing process for form a photoresist film. When fine patterns are formed on a semiconductor device by performing an etching process using the photoresist pattern having the defects, resulting patterns may also have defects. When there is a defect in forming the photoresist pattern, a reworking process may be performed on a semiconductor substrate, in which a photoresist pattern is reformed after the photoresist pattern is removed from the semiconductor substrate.
Removal of the photoresist pattern to rework the semiconductor substrate may be performed using a combination of a dry cleaning process (e.g., an ashing process using oxygen plasma) and a wet cleaning process using organic stripper. When the photoresist pattern is removed by the ashing process using the oxygen plasma, degradation of a semiconductor device may occur due to damage to an exposed surface of the substrate. The ashing process using the oxygen plasma may contribute to the removal of the organic ARC under the photoresist pattern therewith.